Under Rule 3, how is "underway" defined?

The definition of "underway" as indicated in Rule 3 of the COLREGs refers specifically to a vessel that is not at anchor, not made fast to the shore, and not aground. This definition is crucial for understanding the responsibilities and navigation rules that apply to vessels when they are operational in a navigable condition.

When a vessel is considered "underway," it implies that it is capable of moving independently and can respond to maneuvers and navigational rules. This status impacts the application of various COLREGs rules that dictate how vessels should interact with one another in different situations.

The other choices do not meet the criteria for being classified as "underway." A vessel that is at anchor, made fast to the shore, or aground is not considered to be in a position to navigate actively or respond to navigational commands, thus falling outside the definition of "underway." This distinction is essential in maritime navigation to ensure safety and compliance with the regulations designed to prevent collisions at sea.